LPC 1114 ADC Interface

[lpcware]

Content originally posted in LPCWare by diodedan on Sat Sep 18 18:23:40 MST 2010
Hello,

I have two questions:

1) It looks like the ADC of the LPC 1114 is only a single supply ADC (no differential mode). Is this true, or am I missing something?

2) I am using a single supply analog system referenced at Vcc/2 (3.3/2  = 1.65V). I would like to have my output codes read as if they were referenced at zero. I am thinking that at startup, I should read the ADC a few times, average it, and use this as a constant factor to subtract from my ADC reading.

Does anyone have any suggestions/experience with this matter?

Thank you,
Diodedan

[lpcware]

Content originally posted in LPCWare by Ex-Zero on Sat Sep 18 19:11:18 MST 2010
@1: You're right, unfortunately no differential input.

@2: You could use 2 inputs to read voltage / reference voltage and then just subtract them (that's differential, too).